Welding is a method of joining, or separating, metal objects. Arc welding is a common type of welding. An arc welding system typically is comprised of a power supply coupled by an electrical cable to a welding gun housing an electrode. A ground cable is used to connect the metal object to the power supply. The electrode in the welding handle completes an electrical circuit between the power supply and the metal object when the electrode is placed against the metal object, allowing electrical current to flow through the electrode and metal object. The electrical current produces an arc between the electrode and the metal object. The heat of the electric arc melts the object in the region surrounding the electric arc. A filler material may be added to the molten metal. For example, a wire may be placed against the molten portion of the object, melting the wire and allowing the molten wire to merge with the molten object. The circuit is broken and the molten mass begins to cool and solidify when the electrode is drawn away from the metal object, forming a weld.
There are several different types of welding systems and techniques. For example, MIG (Metal Inert Gas) welding is one type of arc welding. MIG welding is also referred to as “wire-feed” or GMAW (Gas Metal Arc Welding). In MIG welding, a metal wire is used as the electrode to produce the arc. Other welding systems use a rigid metal rod as the electrode. In MIG welding, for example, the weld area is shielded by an inert gas and the metal wire acts as a filler to add mass to the weld. The inert gas is used to shield the molten metal from outside contaminants and gases that may react with the molten material of the weld.
Many welding systems utilize a hand-held welding gun. Typically, the welding gun has a switch, or trigger, that is used to control the operation of the system. In MIG welding, for example, the wire and gas are fed to the welding gun from a wire feeder. The wire feeder is, in turn, coupled to a power source and a source of gas, such as a gas cylinder. The welding gun in a MIG system is used to direct the wire and gas to a desired location for welding. When the trigger is operated, wire is fed from the wire feeder to the welding gun. The gas and wire are directed to a workpiece by a neck secured to the handle. In other types of welding, flux, rather than gas, may be conveyed through the welding cable.
Different users have different preferences when it comes to holding the welding handle and operating the trigger. For example, some users may prefer holding the welding gun with their hand close to the trigger, while others may prefer to hold the welding gun further away from the trigger. In addition, a significant amount of heat may be generated within the handle of a welding gun, especially near the neck. Typically, a user will wear a welding glove to protect their hand from the heat produced during the welding. In addition, a user may try to hold the handle as far away from the neck as possible, but still within reach of the trigger.
In addition, the triggers of welding guns are typically spring biased. Typically, a user must overcome the spring bias to depress the trigger and initiate welding. Consequently, trigger locks have been developed to hold a trigger locked in a depressed position so that a user does not have to squeeze the trigger for an extended period of time. A typical trigger lock may have a stem, such as a pin, that extends through the trigger into a portion of the handle to maintain the trigger pivoted.
However, operation of a trigger or trigger lock may be difficult when wearing a welding glove. In addition, assembling the welding gun with the trigger locking assembly may be time-consuming. For example, to assemble the welding gun, the trigger and stem must be positioned in the welding handle so that the locking stem will be able to align with the hole in the welding handle.
There is a need for a welding gun that produces less heat and/or which enables a user to place their hands further away from a source of heat than existing welding guns. Additionally, there is a need for a trigger and trigger lock that may be operated easily by a user wearing a welding glove.